4/15/20131Sharq Elneil CollegeSchool of Medical Laboratory SciencesDepartment of MicrobiologyMedical Bacteriology courseMr.Mahadi Hassan MahmoudBsc, Msc, MIBMS Microbiology08 April 2014genus yersinia includes yersinia pestis, the cause ofplauge y.pseudotuberculosis y.enterocolitica, importantcauses of diarrhoeal disease
4/15/20132 francisella tularensisoccasionally causes septicinfections. several species of pasteurlla areprimarily animal pathogens butalso causes human disease. Gram-negative rod short, pleomorphic Intracellular pathogen Zoonotic infection exhibit bipolar staining. they are catalase positive, oxidase negative, microaerophilic or facultative anaerobic.
4/15/20133 World-wide problem India has had latest scare (100sinfected) Sporadic cases in the U.S., south-western mostly Usually associated with contact withsquirrels and other urban animals
4/15/20134Flea biteBacilli travel to lymph nodesInfection results in swellingand pain (Bubo seen in picturebelow)High fever, chills, headache,nausea
4/15/20135 Clinical Syndromes(Septicemic Plague)Can penetrate and invadebloodstream All organs infected Lungs (secondary pneumonicplague) Danger to close contacts Clinical Syndromes (PrimaryPneumonic Plague) Spread via respiratory droplets 1 bacilli can cause disease in patient Severe hemorrhaging Death in hours 100% mortality if untreated, or latetreatment
4/15/2013650-75% mortality when it goes tobloodstream Endotoxin shock primary problemIntravascular coagulationMulti-organ failure“bruising” on skin……this is howit got the name the ”black death”See the same thing with NeisseriameningitidisYersinia pestis and plaugePlauge is an infection of wildrodents, rodents, rodents,transmitted from one rodent toanother and occasionally fromrodent to human by the bites offleas (black death).
4/15/20137I. Bubonic Plague: Interhuman Transmission:> Bubonic Disease >PneumonicPlague > Exhales the Organism inDroplets. Pestis Minor:ii. Septicaemic Plague:iii. Pneumonic Plague:SymptomsAfter i.p of 2-7days,there is high feverand painful lymphadenopathy,common with greatly enlarged, tendernodes (buboes) in the groin of axillae.vomiting and diarrhoea may occur withearly sepsis. later D.I.C. lead tohypotension, renal and cardiac failure.y. p, multiplies intravascular and can beseen in B. smears.
4/15/20138Specimens: Blood is taken for culture Aspirates of enlarged lymph nodesfor smear and culture. Acute and convalescent sera may beExamined for antibody level Pneumonia sputum is cultured, Meningitis C.S.F is taken for smearand culture. Stained with giemsa waysons I.F stain.
4/15/20139Culture: all materials are cultured on B.A MaCconkey infusion broth.on solid media growth is slow but b.cultures are often positive in 24hrs.Serology:
4/15/201310Sensetive to streptomycin. Tetracycline some times given incombination.
4/15/201311A Quarantinable Disease. Control of Urban Plague: Garbage Disposal.Y. enterocolitica and Y. pseudotuberculosis These are non lactose fermenting G-ve rods that are Urase+ and Oxid-.They grow best at 25 cand alsomotile, but not motile at37c, Diagnostic tests: Specimen, culture, serology. Treatment: most yersiniae infectionswith diarrheal are self limited.
4/15/201312Francisella Tularensis andTularemia F.Tularences, is widely found in animalreservoirs and transmitted to human bybiting arthropods, inhalation or ingestionof contaminated water or food.Morphology and identification F.T, is small G-ve pleomorphic rods, itrarely seen in smears of tissue.Specimen: blood is taken for serologic tests.Culture: growth does not occur in mostordinary media small colonies appear in 1-3 days onglucose cysteine B.A incubated 37cunder aerobic condition. the organism identified usually by itsgrowth requirement and I.F stain. Caution: the organism is highlyinfectious.
4/15/201313Serology: there is one or more AG can crossreact with brucella.Diagnostic tests: generally smears and cultures arenot contributory diagnostic tests rests on serology,paired serum collected 2 weeksapart can show arise in titer, titer of1:60 is highly suggestive.AntibiogramSensetive to: Streptomycin Gentamicin Tetracycline equally effective, butrelapses occur morely frequently. Ceftriaxone is not effective.
4/15/201314 These are primarily animal pathogens non motile G-ve coco bacilli They are aerobe and facultativeanaerobe they are grow in ordinarymedia at 37c .they are O+ve, Cat+ve.Pathology The most common presentation is a historyof animal bite followed by an acute onsetof redness, swelling and pain, fever is oftenlow grade, lymphadenopathy is variable.infections some times present asbacteremia or chronic respiratory infectionwithout an evident connection withanimals.